Compound for hardening iron.



Application filed M1 ch17, 1905. Serial No- 250,600-

To aZZ whom it may concern:

Be it known that we, CORNELIUS A. B NS and CoRNELIUs E. RAAB, citizensof United States of America, residing at burg, in the county ofAllegheny and Sta Pennsylvania, have invented certain ne usefulImprovements in Compounds for l ardening Iron, of which the following is2. sp ification. y l;

This invention has relation to a compo, nd for hardening iron, and hasfor its prind pal object the provision of a novel compoun for hardeningcast-iron of the ordinary qu and cast-iron of that character knowmalleable cast-iron. i We are aware that it has been propose hardencast-iron by sub'ecting the sami to the chemical action 0 certainmatelals while the iron is in a heated state; bu; we are unaware of anycomposition which impart to malleable casting or to malleii cast-ironthe degree of hardness which we impart by the means hereinafterdescribed? In carrying our invention into effectvwe prepare a compoundcomposed of the foll wgiven after each: chlorid of so ium, t

. ing materials, preferably in the roportlifins 66 potassium, one part.

a as

parts; saltpeter, three parts; rockal In, three'parts; carbonate ofammonia, t ee parts; salt of tartar, three parts ,yel ow prussiate ofpotassium, one part; White eyanid of potassium, one part; red prussia ofThese materialsl'are thoroughly mixed together, and'the iro be temperedis heated to a red heat Tapproximating a cherry red, and thecomposition, which has been reduced to a powdery form, is sprinkled uponthe iron and allowed to remain in contact with the same a sllort time,and the iron is then dipped into consisting o ELIUS E. RAAB, OFPITTSBURG, PENN;

LVANIA.

Patented Nov. 28, 1905.

water, whereupon it will be tempered and given a hardness approximatinto or even exceeding that of hard tool-stee the degree of hardness beingdependent upon the length of time to which the iron has been subjectedto the action of the compound above described and to the action of thewater.

While we have found that the composition given above in the proportionsspecified gives eminently satisfactory results, we do not wish to belimited to the precise composition as it is set forth above, as certainvariations of the materials used and the proportions specified may bemade without departing from the spirit of'our invention.

What we claim is .1. A compound for hardening cast-iron consisting ofthree parts chlorid of sodium, three parts saltpeter, three partsrock-alum, three parts carbonate of ammonia, three parts salt of tartar,one part yellow prussiate of potassium, one part white cyanid ofpotassium and one part red prussiate of potassium.

2. A com ound for hardening cast-iron i chlorid of sodium, saltpeter,rock-alum, carbonate of ammonia, salt of tartar, yellow prussiate ofpotassium, cyanid of potassium and red prussiate of potassium.

3. A compound for hardening iron con' taining chlorid of sodium, saltpeter, alum, carbonate of ammonia, salt of tartar, prussiate of potashand cyanid of potassium.

In testimony whereof we aflix our signatures in the presence of twowitnesses.

A Witnesses:

H. C. EVERT,

POTTER.

